Production for producing 3-cyano-4-phenyl indoles and intermediates

ABSTRACT

There is described a process for producing fungicidally active 4-phenylpyrrole derivatives of the formula I ##STR1## wherein R is halogen, C 1  -C 6  -alkyl or C 1  -C 6  -haloalkyl, and n is 0, 1 or 2, which process comprises reacting a 3-trifluoromethyl-4-phenylpyrrole of the formula II ##STR2## wherein R n  is as defined under the formula I, and R 1  is hydrogen or an acyl group, at elevated temperature and elevated pressure, with ammonia. Important intermediates and the production thereof are also described.

The present invention relates to a novel process for producing4-phenylpyrrole derivatives of the formula I ##STR3## wherein R ishalogen, C₁ -C₆ -alkyl or C₁ -C₆ -haloalkyl, and

n is 0, 1 or 2.

By the term `alkyl` itself or alkyl as a constituent of anothersubstituent, such as haloalkyl, and so forth, are meant, depending onthe given number of carbon atoms, for example the followingstraight-chain or branched-chain groups: methyl, ethyl, propyl, butyl,pentyl, hexyl, and the like, as well as isomers thereof, for example:isopropyl, isobutyl, tert-butyl, isopentyl, and so forth. The prefix`halo` in the designation of a substituent signifies, here and in thefollowing, that this substituent can occur mono- to perhalogenated.Halogen and halo represent in particular fluorine, chlorine or bromine.Haloalkyl hence denotes a mono- to perhalogenated alkyl group, such as:CHCl₂, CH₂ F, CCl₃, CH₂ Cl, CHF₂, CH₂ CH₂ Br, C₂ Cl₅, CHBr₂, CHBrCl, andso forth, preferably CF₃.

4-Phenylpyrrole derivatives of the formula I wherein n is 0, 1 or 2, andthe pyrrole nitrogen is unsubstituted or substituted by acetyl, areknown from the German Offenlegungsschrift No. DE-OS No.2,927,480.sup.(1) as plant fungicides.

In the German Offenlegungsschrift No. 2,927,480.sup.(1), there ismentioned a process for producing 4-phenyl-3-cyanopyrrole derivatives,which is known from Tetrahedron Letters No. 52, pp. 5337-5340,1972.sup.(2). In this process, known as the TosMIC process, a cinnamicacid nitrile of the formula X ##STR4## is cyclised withtosylmethylisocyanide (XX) [TosMIC], in the presence of a strong base,for example sodium hydride, to 4-phenyl-3-cyanopyrrole derivatives ofthe formula (XXX), the symbol R having the meanings defined under theformula I, and n being 0, 1 or 2.

Although a great number of pyrrole syntheses are known (cf. J. M.Patterson, Synthesis, 1976, pp. 281-304.sup.(3)), only the TosMICprocess outlined above has hitherto resulted directly in thefungicidally valuable 4-phenyl-3-cyanopyrrole derivatives unsubstitutedin the 2- and 5-positions. Nevertheless, there is stated in reference(2), with respect to the production of the starting material,4-phenyl-3-cyanopyrrole, the yield of 35%, which is low for commercialpurposes. It has also been shown that the reagent TosMIC has seriousdisadvantages for commercial syntheses. Thus, TosMIC is subject atelevated temperature, especially above 90° C. (customary dryingconditions), to explosive decomposition. On the other hand, residualmoisture uses up a portion of the employed base (risk ofhydrolysis/reduction in yield). Furthermore, TosMIC has physiologicaldisadvantages, such as irritation to the eyes and skin.

As a result of the disadvantages mentioned, the in itself usefullaboratory process is unsuitable for the industrial production of4-phenylpyrrole derivatives.

There has now been found a novel, more economical and ecologically morefavourable process, by which are obtained surprisingly high yields.

The novel process according to the invention for producing the4-phenylpyrrole derivatives of the formula I defined at the beginning ofthe text comprises reacting a 3-trifluoromethyl-4-phenylpyrrole of theformula II ##STR5## wherein R is halogen, C₁ -C₆ -alkyl or C₁ -C₆-haloalkyl,

n is 0, 1 or 2, and

R₁ is hydrogen or acyl, preferably the group C(O)R₂, in which R₂ is C₁-C₆ -alkyl, C₁ -C₆ -haloalkyl, phenyl or C₁ -C₆ -alkoxy,

at elevated temperature and elevated pressure, with ammonia.

Suitable acyl groups are in general all arylcarbonyl, aralkylcarbonyl,alkylcarbonyl and alkoxycarbonyl groups which are unsubstituted orsubstituted by customary substituents (such as: halogen, cyano, loweralkoxy, lower alkylthio, lower haloalkyl or nitro).

Surprisingly in this reaction, the trifluoromethyl group in the3-position of the pyrrole ring is converted into a cyano group, andsimultaneously the acyl group on the pyrrole nitrogen (R₁ =acyl,preferably C(O)R₂) is cleaved off, so that there are directly obtainedthe fungicidally active 4-phenylpyrrole derivatives mentioned inreference (1), which, so far as N-acetylated derivatives are desired,can be subsequently acetylated in the customary manner, for exampleaccording to reference (1).

The reaction according to the invention is advantageously performed attemperatures of between room temperature and +230° C., particularlybetween +160° C. and +200° C.

The reaction is preferably performed in a solvent or solvent mixtureinert to the reactants. Suitable solvents are for example: aliphatic andaromatic hydrocarbons, such as benzene, toluene, xylenes, petroleumether, and so forth; ethers and ethereal compounds, such as dialkylether (diethyl ether, diisopropyl ether, tert-butylmethyl ether, and thelike), anisole, and especially cyclic ethers, such as dioxane ortetrahydrofuran; alcohols, such as alkanols (methanol, ethanol,propanols, butanols, and so forth), and water, and also mixtures of suchsolvents with one another.

The pressure range suitable for this reaction is between 1 and 200 bar;with the present of water preferably between 1 and 50 bar; with theabsence of water preferably between 40 and 150 bar.

In a preferred embodiment, there is used aqueous ammonia, preferably aconcentrated aqueous ammonia solution (about 25 to 34 percent by weightof NH₃) in dioxane or tetrahydrofuran. The ammonia can however beproduced in the reaction mixture, for example from an ammonium salt, forexample an ammonium halide (NH₄ Cl) and a base (for example NaOH).

The ammonia is generally used in excess, at least however in equimolaramounts; and the reaction is performed in customary pressure vessels,for example bomb tubes, autoclaves, etc.).

A particularly preferred embodiment comprises reacting3-trifluoromethyl-4-(2,3-dichlorophenyl)pyrrole, or a derivative thereofN-acylated by C(O)R₂, wherein R₂ has the meanings defined under theformula II, at +50° to +230° C., preferably +160° to +200° C., withexcess aqueous ammonia in a cyclic ether, preferably dioxane ortetrahydrofuran, and in a closed pressure vessel, to obtain3-cyano-4-(2,3-dichlorophenyl)pyrrole.

The starting materials of the formula II are novel: they are plainlypredestined, by virtue of the conversion according to the invention ofCF₃ into CN, to be used as starting products for producing the compoundsof the formula I. They have valuable fungicidal properties and likewiseform subject matter of the present invention. The compounds of theformula II can be produced for example by reacting a benzaldehyde of theformula III ##STR6## with an organyloxymethyl-triphenylphosphoniumhalide of the formula IV ##STR7## to a styrene derivative of the formulaV ##STR8## acetylating this, in the presence of a base, withtrifluoroacetic anhydride to a compound of the formula VI ##STR9##cyclising (VI) with an alkali glycinate, preferably a sodium orpotassium glycinate, in a carboxylic anhydride of the formula VII

    O[C(O)R.sub.2 ].sub.2                                      (VII)

to an N-acylated 3-trifluoromethyl-4-phenylpyrrole of the formula II'##STR10## and, if desired, cleaving off basically the acyl group C(O)R₃,so that there is formed a free 3-trifluoromethyl-4-phenylpyrrole of theformula II" ##STR11## R_(n) in the formulae III, V, VI, II' and II" andR₂ in the formulae VII and II' having the meanings defined under theformula I, R₃ in the formula IV being an organyl radical, preferably anaromatic or aliphatic radical, particularly C₁ -C₁₂ -alkyl, aralkyl orphenyl, especially C₁ -C₆ -alkyl, which is unsubstituted or substitutedby customary radicals, and Hal in the formula IV being halogen,preferably chlorine, bromine or iodine.

The described process for producing the compounds of the formula IIconstitutes a part of this invention.

The reaction of the benzaldehyde III with theorganyloxymethyl-triphenylphosphonium halide IV to styrene derivativesof the formula V can be performed analogously to the reactions describedin Chem. Ber. 94, 1373 (1961), and is described explicitly in thefollowing by way of an example.

The benzaldehydes of the formula III, theorganyloxymethyl-triphenylphosphonium halides of the formula IV and alsothe anhydrides of the formula VII are in general known, and can beproduced in a manner analogous to that for obtaining the knownrepresentatives.

The trifluoroacetylation of the styrenes V to give compounds of theformula VI is however novel. It results in high yields but, contrary tocustomary acetylation reactions, only with the exclusion of solvents, ata temperature of between about +20° and +150° C., preferably between+80° and +120° C., and under elevated pressure. The reaction isgenerally performed with equimolar amounts of trifluoroacetic anhydride,or advantageously with an excess thereof, in a bomb tube, in anautoclave or in some other pressure vessel. The use of acid-freetrifluoroacetic anhydride is of advantage. The bases in this reactioncan be organic or inorganic, and they are preferably used in anequimolar amount. Suitable bases are for example inorganic bases, suchas the oxides, hydrides, carbonates and carboxylic acid salts ofalkaline-earth metals, preferably of alkali metals, especially of sodiumand potassium [for example: NaH, Na₂ CO₃, K₂ CO₃, CaCO₃, CH₃ COONa, C₂H₅ COOK, etc.]. Applicable organic bases are trialkylamines, for exampletriethylamine, piperidine and in particular pyridine bases, such as freepyridine. Since the reaction of (V) to (VI) is novel, resulting indirect precursors (VI) of the fungicidally active compounds of theformulae II' and II", it forms an important component of the presentinvention. In the same way, the compounds of the formula VI as directintermediates for the fungicidally active compounds of the formulae II'and II" likewise form subject matter of the present invention.

The reaction of the compound of the formula VI with an alkali glycinateand the carboxylic anhydride VII can either be performed by thesingle-vessel process, wherein all three reactants (VI+glycinate+VII)are simultaneously present, compounds of the formula II' being obtaineddirectly in this manner, or be performed by firstly reacting (VI) withthe glycinate to give an intermediate VIII capable of being isolated##STR12## wherein R_(n) has the meaning defined under the formula I, andM is an alkali metal atom, especially potassium or sodium, andsubsequently cyclising (VIII), by reaction with the carboxylic anhydrideVII, to obtain compounds of the formula II. Pyrrole syntheses of thistype are known from the literature [cf. Helv. Chem. Acta. 65, 1694(1982)], and can be carried out by methods analogous to those describedtherein.

Compounds of the formula II" are produced from compounds of the formulaII' by basic cleavage of the acyl group C(O)R₂. This basic cleavage canbe effected completely analogously to protective-group cleavages knownfrom the literature [cf. Hel. Chem. Acta 65, 407 and 1694 (1982)]. Thereaction is generally performed at temperatures of between -20° and+100° C. in customary organic solvents inert to the reactants, and thebase used can be one of the organic or inorganic bases mentioned in theforegoing, preferably lithium aluminium hydride.

PRODUCTION OF THE PRECURSORS Example P1 Production of ##STR13##β-Methoxy-2,3-dichlorostyrene

47.3 g of sodium methylate are introduced into 1.5 liters of absoluteethanol. There are then added portionwise, at room temperature, firstly300.0 g of methoxymethyltriphenylphosphonium chloride and afterwards142.5 g of 2,3-dichlorobenzaldehyde, and the reaction mixture is heatedat 70° C. for about 60 hours. After cooling to room temperature, themixture is filtered, and the filtrate is concentrated in vacuo. Theresidue is taken up in pentane, washed, again concentrated byevaporation, and filtered over SiO₂ with dichloromethane. Excess solventis removed in vacuo. There is thus obtainedβ-methoxy-2,3-dichlorostyrene as a 1:1 (E/Z) mixture in the form of alight-yellow oil.

Example P2 Production of ##STR14##α-Trifluoroacetyl-β-methoxy-2,3-dichlorostyrene

6.1 g of pyridine are added in a bomb tube to 13.5 g of theβ-methoxy-2,3-dichlorostyrene produced above. To this mixture are addeddropwise, in an argon gas protective atmosphere and with cooling, 24.4 gof trifluoroacetic anhydride. The bomb tube is sealed, and heated at100° C. for 4 hours. After cooling to room temperature, the reactionmixture is taken up in dichloromethane, and filtered through SiO₂. Thesolvent is evaporated off to thus obtainα-trifluoroacetyl-β-methoxy-2,3-dichlorostyrene as yellow oil.

Example P3 Production of ##STR15##N-Acetyl-4-(2,3-dichlorophenyl)-3-trifluoromethylpyrrole

2.7 g of glycine and 2.0 g of potassium hydroxide are dissolved in 160ml of ethanol, and the mixture is heated to 45° C. There are then addedat this temperature 9.9 g of theα-trifluoroacetyl-β-methoxy-2,3-dichlorostyrene produced according toExample P2, and the reaction mixture is refluxed for 90 minutes. Themixture is subsequently concentrated in vacuo; to the residue areafterwards added 150 ml of acetic anhydride, and the new mixture isheated at 100° C. for 45 minutes. After the evolution of CO₂ hassubsided, the solvent is removed by evaporation, and the residue istaken up in toluene, and filtered through SiO₂. The filtrate is againconcentrated by evaporation, and the oily residue is covered withhexane, in the course of whichN-acetyl-4-(2,3-dichlorophenyl)-3-trifluoromethylpyrrole precipitates inthe form of beige crystals, m.p. 65°-66° C.

Example P4 Production of ##STR16##3-Trifluoromethyl-4-(2,3-dichlorophenyl)-pyrrole

29.0 g of N-acetyl-4-(2,3-dichlorophenyl)-3-trifluoromethylpyrrole aredissolved in 500 ml of diethyl ether. This solution is subsequentlycooled to 0° C., and to it are added portionwise 13.7 g of lithiumaluminium hydride. The mixture is afterwards stirred for 1 hour, andthere are then added dropwise at 5° C. 55 ml of 4% sodium hydroxidesolution, in the course of which elementary hydrogen is given off, andthe mixture is subsequently stirred for a further hour at roomtemperature. The mixture is then filtered; the filtrate is dried overmagnesium sulfate, again filtered, and concentrated by evaporation. Theresulting oil is distilled at 150°/8×10⁻⁵ mbar. By covering it withhexane, there is obtained from the distillate3-trifluoromethyl-4-(2,3-dichlorophenyl)pyrrole in the form ofcolourless crystals, m.p. 63°-65° C.

By procedures analogous to those described in the foregoing, there arealso obtained the following representatives of compounds of the formulaVI, which are typical for the present ivention, ##STR17## the compoundsbeing obtained in general in the form of 1:1 (E/Z) mixtures.

    ______________________________________                                        Comp. No.        R.sub.n     R.sub.3                                          ______________________________________                                        1.1              H           CH.sub.3                                         1.2              H           C.sub.3 H.sub.7 -n                               1.3              3-Cl        CH.sub.3                                         1.4              2-Br        CH.sub.3                                         1.5              2,5-Cl.sub.2                                                                              CH.sub.3                                         1.6              2,3-Cl.sub.2                                                                              CH.sub.3                                         1.7              2-Cl        CH.sub.3                                         1.8              3-CF.sub.3  CH.sub.3                                         1.9              3-Br        CH.sub.3                                         1.10             3-F         CH.sub.3                                         1.11             3-CH.sub.3  CH.sub.3                                         1.12             4-F         CH.sub.3                                         1.13             4-Cl        CH.sub.3                                         1.14             2,4-Cl.sub.2                                                                              CH.sub.3                                         1.15             2,3-Cl.sub.2                                                                              C.sub.2 H.sub.5                                  1.16             2,3-Cl.sub.2                                                                              C.sub.3 H.sub.7 -i                               1.17             2,3-Cl.sub.2                                                                              C.sub.6 H.sub.5                                  1.18             2-Cl        C.sub.6 H.sub.5                                  ______________________________________                                    

By procedures analogous to those described are obtained also thefollowing representatives of the formula II which are typical for thepresent invention:

    ______________________________________                                         ##STR18##                    (II)                                            Comp. No.                                                                             R.sub.n  R.sub.1     Physical constants                               ______________________________________                                        2.1     2,3-Cl.sub.2                                                                           H           m.p. 63-65° C.                            2.2     2-Br     H                                                            2.3     2,5-Cl.sub.2                                                                           H                                                            2.4     2-Cl     H           m.p. 93-94° C.                            2.5     2-CF.sub.3                                                                             H                                                            2.6     3-Br     H                                                            2.7     3-F      H                                                            2.8     3-CH.sub.3                                                                             H                                                            2.9     4-F      H                                                            2.10    4-Cl     H                                                            2.11    2,4-Cl.sub.2                                                                           H                                                            2.12    3-Cl     H                                                            2.13    H        H                                                            2.14    2,3-Cl.sub.2                                                                           C(O)CH.sub.3                                                                              m.p. 65-66° C.                            2.15    2-Br     C(O)CH.sub.3                                                 2.16    2,5-Cl.sub.2                                                                           C(O)CH.sub.3                                                 2.17    2-Cl     C(O)CH.sub.3                                                                              b.p. 130-140°/0,01 mbar                   2.18    2-CF.sub.3                                                                             C(O)CH.sub.3                                                 2.19    3-Br     C(O)CH.sub.3                                                 2.20    3-F      C(O)CH.sub.3                                                 2.21    3-CH.sub.3                                                                             C(O)CH.sub.3                                                 2.22    4-F      C(O)CH.sub.3                                                 2.23    4-Cl     C(O)CH.sub.3                                                 2.24    2,4-Cl.sub.2                                                                           C(O)CH.sub.3                                                 2.25    3-Cl     C(O)CH.sub.3                                                 2.26    2,3-Cl.sub.2                                                                           C(O)CH.sub.3                                                 2.27    2,3-Cl.sub.2                                                                           C(O)C.sub.3 H.sub.7i                                         2.28    2,3-Cl.sub.2                                                                           C(O)C.sub.6 H.sub.5                                          2.29    2,3-Cl.sub.2                                                                           C(O)OCH.sub.3                                                2.30    3-Cl     C(O)OC.sub.2 H.sub.5                                         2.31    3-Cl     C(O)C.sub.6 H.sub.5                                          2.32    3-Cl     C(O)CF.sub.3                                                 2.33    2-Cl     C(O)C.sub.4 H.sub.9n                                         2.34    2-Cl     C(O)OC.sub.3 H.sub.7n                                        2.35    2-Cl     C(O)C.sub.2 H.sub.5                                          2.36    2,3-Cl   C(O)CF.sub.3                                                 2.37    H        C(O)CH.sub.3                                                                              b.p. 110-120°/0,01 mbar                   ______________________________________                                    

The novel pyrrole derivatives of the formula II according to theinvention constitute a valuable enlargement of the prior art, for it hasbeen established that the novel pyrroles of the formula II surprisinglyexhibit a microbicidal spectrum against phytopathogenic fungi andbacteria which is very favourable for agricultural requirements. Theynot only can be used in arable farming or in similar fields ofapplication for controlling harmful microorganisms on cultivated plants,but can be additionally used, in the protection of stocks, forpreserving perishable goods. Compounds of the formula II have veryadvantageous curative, systemic and in particular preventive properties,and can be used for the protection of numerous, especially arable,crops. The microorganisms occurring on plants or on parts of plants(fruit, blossom, foliage, stalks, tubers or roots) of various cultivatedcrops can be inhibited or destroyed with the active substances of theformula II, and also parts of plants subsequently growing remainpreserved from such microorganisms.

The active substances are effective for example against thephytopathogenic fungi belonging to the following classes: Ascomycetes,for example Erysiphe, Sclerotinia, Fusarium, Monilinia andHelminthosporium; Basidiomycetes, for example Puccinia, Tilletia andRhizoctonia; and also against the Oomycetes belonging to thePhycomycetes class, such as Phytophthora. As plant protective agents,the compounds of the formula II can be applied with a particularly highdegree of success against important harmful fungi from the Fungiimperfecti family, for example against Cercospora or Piricularia, andespecially against Botrytis. Botrytis spp. (B. cinera, B. allii)constitute with botrytis disease on grapevines, strawberries, apples,onions and other fruit and vegetable varieties a significant economicloss factor. Furthermore, some compounds of the formula II can besuccessfully used for protecting perishable goods of vegetable or animalorigin. They combat mould fungi, such as Penicillium, Aspergillus,Rhizopus, Fusarium, Helminthosporium, Nigrospora and Alternaria, as wellas bacteria, such as butyric acid bacteria, and yeasts, such as Candida.

As plant protective agents, the compounds of the formula II exhibit, forpractical application in agriculture, a very favourable spectrum ofactivity for protecting cultivated plants, without disadvantageouslyaffecting these by undesirable side effects.

The compounds can also be used as dressing agents for the treatment ofseed (fruits, tubers or grain), and of plant cuttings to protect themfrom fungus infections, and also against phytopathogenic fungi occurringin the soil.

The invention thus relates also to microbicidal compositions, and to theuse of the compounds of the formula II for controlling phytopathogenicmicroorganisms, especially fungi which damage plants, and for preventingan infestation on plants and on provisions of vegetable or animialorigin.

In addition, the present invention embraces also the production of(agro)chemical compositions, whereby the active ingredient is intimatelymixed with one or more substances or groups of substances describedherein. Also included is a process for treating plants or storedprovisions, which process comprises the application of the compounds ofthe formula II, or of the novel compositions, to the plants or parts ofplants, or to the locus or the substrate thereof.

Within the scope of this invention, target crops for plant protectionare for example the following varieties of plants: cereals (wheat,barley, rye, oats, rice, sorghum and related cereals); beet (sugar beetand fodder beet); pomaceous fruit, stone fruit and soft fruit (apples,pears, plums, peaches, almonds, cherries, strawberries, raspberries andblackberries); legumes (beans, lentils, peas and soya-beans); oil plants(rape, mustard, poppy, olives, sunflowers, coco, castor-oil plants,cocoa and groundnuts); Curcurbitacea (pumpkins, cucumbers and melons);fibre plants (cotton, flax, hemp and jute); citrus fruits (oranges,lemons, grapefruit and mandarins); varieties of vegetables (spinach,lettuce, asparagus, varieties of cabbage, carrots, onions, tomatoes,potatoes and paprika); laurel plants (avocada, cinnamon and camphor); orplants such as maize, tobacco, nuts, coffee, sugar cane, tea,grapevines, hops, bananas and natural rubber plants; and also ornamentalplants (composites).

As protective agents for stored products, the compounds of the formulaII are used either in an unmodified form or preferably together withauxiliaries customarily employed in formulation practice, and are thusprocessed, in a known manner, for example into the form of emulsionconcentrates, brushable pastes, directly sprayable or dilutablesolutions, diluted emulsions, wettable powders, soluble powders, dustsor granulates, and also encapsulations in for example polymericsubstances. The application processes, such as spraying, scattering,brushing or pouring, and likewise the type of composition, are selectedto suit the objectives to be achieved and the prevailing conditions.Favourable applied amounts are in general 0.01 to at most 2 kg of activeingredient per 100 kg of substrate to be protected; the amounts dependhowever quite considerably on the nature (extent of surface area,consistency, and moisture content) of the substrate and on enviromentalinfluences thereon.

Within the scope of the present invention, stored stocks and provisionsare vegetable and/or animal natural materials and products from furtherprocessing, for example the plants which are listed in the following andwhich have been taken out from the natural life cycle, and parts ofthese plants (stalks, leaves, tubers, seeds, fruits and grains), thematerials being in the freshly harvested condition or in the formresulting from further processing (pre-dried, moistened, crushed, groundor roasted). The following productive materials may be given asexamples, which however have no limiting character with respect to thescope of this invention: cereals (such as wheat, barley, rye, oats,rice, sorghum and related cereals); beet (such as carrots, sugar beetand fodder beet); pomaceous fruit, stone fruit and soft fruit (such asapples, pears, plums, peaches, almonds, cherries, strawberries,raspberries and blackberries); legumes (such as beans, lentils, peas andsoya-bean); oil plants (such as rape, mustard, poppy, olives,sunflowers, coco, castor-oil plants, cocoa and groundnuts); Cucurbitacea(such as pumpkins, cucumbers and melons); fibre plants (such as cotton,flax, hemp, jute and nettles); citrus fruits; varieties of vegetables(such as spinach, lettuce, asparagus and varieties of cabbage, onions,tomatoes, potatoes and paprika); laurel plants (such as avocada,cinnamon and camphor); or plants such as maize, tobacco, nuts, coffee,sugar cane, tea, grapevines, chestnuts, hops, bananas, grass and hay.

Natural products of animal origin which may be mentioned are inparticular dried processed meat and fish products, such as dried meat,dried fish, meat concentrates, bone meal, fish meal and dried animalfeed.

By treatment with compounds of the formula II, the treated storedproducts are lastingly protected against infestation by mould fungi andother undesirable microorganisms. Consequently, the formation of toxicand in part carcinogenic mould fungi (aflatoxines and ochratoxines) isprevented, the material is kept from decomposing, and the qualitythereof is maintained high for a prolonged period of time. The processaccording to the invention can be applied to all dry and moistprovisions and stored goods which are susceptible to microorganisms,such as yeasts, bacteria and especially mould fungi.

A preferred process for applying the active substance comprises sprayingor wetting the substrate with a liquid preparation, or mixing thesubstrate with a solid preparation of the active substance. Thedescribed conservation process forms a part of the present invention.

Active substances of the formula II are customarily used in the form ofcompositions, and can be applied, simultaneously or successively, withfurther active substances to the area or plants to be treated. Thesefurther active substances can be fertilisers, trace-element agents orother preparations influencing plant growth. They can however also beselective herbicides, insecticides, fungicides, bactericides,nematicides or molluscicides, or mixtures of several of thesepreparations, optionally together with carriers commonly used informulation practice, tensides or other additives facilitatingapplication.

Suitable carriers and additives can be solid or liquid and theycorrespond to the substances customarily employed in formulationpractice, for example: natural or regenerated mineral substances,solvents, dispersing agents, wetting agents, adhesives, thickeners,binders or fertilisers.

A preferred method of applying an active substance of the formula II, oran agrochemical composition containing at least one of these activesubstances, is application to the foliage (leaf application). The numberof applications and the amounts applied are governed by the extent ofinfestation with respect to the pathogen (fungus genus) concerned. Theactive substances of the formula II can however be fed into the plantthrough the soil and then by way of the root system (systemic action),this being achieved by the locus of the plant being soaked with a liquidpreparation, or by the substances being introduced in solid form intothe soil, for example in the form of a granulate (soil application). Thecompounds of the formula II can also be applied to the seed grains(coating), the grains being for this purpose either soaked with a liquidpreparation of the active substance or coated with a solid preparation.Further forms of application are possible in special cases, for examplethe specific treatment of the stalks or buds of the plants.

The compounds of the formula II are used either in an unmodified form orpreferably together with auxiliaries customarily employed in formulationpractice, and are thus processed, in a known manner, for example intothe form of emulsion concentrates, brushable pastes, directly sprayableor dilutable solutions, diluted emulsions, wettable powders, solublepowders, dusts or granulates, and also encapsulations in for examplepolymeric substances. The application processes, such as spraying,atomising, dusting, scattering, brushing or pouring, and likewsie thetype of composition, are selected to suit the objectives to be achievedand the given conditions. Favourable applied amounts are in generalbetween 50 g and 5 kg of active substance (AS) per hectare, preferablybetween 100 g and 2 kg of AS per hectare, and in particular between 200g and 600 g of AS per hectare.

The formulations, that is to say, the compositions or preparationscontaining the active substance of the formula II and optionally a solidor liquid additive, are produced in a known manner, for example by theintimate mixing and/or grinding of the active ingredient with extenders,such as with solvents, solid carriers and optionally surface-activecompounds (tensides).

Suitable solvents are: aromatic hydrocarbons, preferably the fractionsC₈ to C₁₂, such as xylene mixtures or substituted naphthalenes, phthalicesters, such as dibutyl- or dioctylphthalate, aliphatic hyrdocarbons,such as cyclohexane or paraffins, alcohols and glycols, as well asethers and esters thereof, such as ethanol, ethylene glycol, ethyleneglycol monomethyl or -ethyl ethers, ketones such as cyclohexanone,strongly polar solvents, such as N-methyl-2-pyrrolidone, dimethylsulfoxide or dimethylformamide, as well as optionally epoxidisedvegetable oils, such as epoxidised coconut oil or soybean oil; or water.

The solid carriers used, for example for dusts and dispersible powders,are as a rule natural mineral fillers, such as calcite, talcum, kaolin,montmorillonite or attapulgite. In order to improve the physicalproperties, it is possible to also add highly dispersed silicic acid orhighly dispersed absorbent polymers. Suitable granulated adsorptivecarriers are porous types, for example pumice, ground brick, sepioliteor bentonite; and suitable nonsorbent carriers are materials such ascalcite or sand. There can also be used a great number of pre-granulatedmaterials of inorganic or organic nature, such as in particular dolomiteor ground plant residues.

Particularly advantageous additives facilitating application andrendering possible a marked reduction in the amount of active substanceapplied are moreover natural (animal or vegetable) or syntheticphospholipides from the class comprising the cephalins and lecithins,for example phosphatidylethanolamine, phosphatidylserine, phosphatidylglycerol, lysolecithin, plasmalogenes or cardiolipin, which can beobtained for example from animal or plant cells, especially from thebrain, heart, liver, egg yokes or soya beans. Applicable commercialmixtures are for example phosphatidylcholine mixtures. Syntheticphospholipides are for example dioctanoylphosphatidylcholine anddipalmitoylphosphatidylcholine.

Depending on the nature of the active ingredient of the formula II to beformulated, suitable surface-active compounds are nonionic, cationicand/or anionic tensides having good emulsifying, dispersing and wettingproperties. By `tensides` are also meant mixtures of tensides.

Suitable anionic tensides are both so-called water-soluble soaps as wellas water-soluble, synthetic, surface-active compounds.

Soaps which are applicable are for example the alkali metal,alkaline-earth metal or optionally substituted ammonium salts of higherfatty acids (C₁₀ -C₂₂), for example the Na or K salts of oleic orstearic acid, or of natural fatty acid mixtures, which can be obtainedfor example from coconut oil or tallow oil. Also to be mentioned are thefatty acid-methyl-taurine salts.

So-called synthetic tensides are however more frequently used,particularly fatty sulfonates, fatty sulfates, sulfonated benzimidazolederivatives or alkylarylsulfonates. The fatty sulfonates or sulfates areas a rule in the form of alkali metal, alkaline-earth metal oroptionally substituted ammonium salts, and contain an alkyl group having8 to 22 C atoms, `alkyl` including also the alkyl moiety of acyl groups,for example the Na or Ca salt of ligninsulfonic acid, of dodecylsulfuricacid ester or of a fatty alcohol sulfate mixture produced from naturalfatty acids. Included among these are also the salts of sulfuric acidesters and sulfonic acids of fatty alcohol ethylene oxide adducts. Thesulfonated benzimidazole derivatives preferably contain 2 sulfonic acidgroups and a fatty acid group having 8-22 C atoms. Alkylarylsulfonatesare for example the Na, Ca or triethanolamine salts ofdodecylbenzenesulfonic acid, of dibutylnaphthalenesulfonic acid or of anaphthalenesulfonic acid-formaldehyde condensation product. Alsosuitable are corresponding phosphates, for example salts of thephosphoric ester of a p-nonylphenol-(4-14)-ethylene oxide adduct.

Suitable nonionic tensides are in particular polyglycol etherderivatives of aliphatic or cycloaliphatic alcohols, saturated orunsaturated fatty acids and alkylphenols, which can contain 3 to 30glycol ether groups and 8 to 20 carbon atoms in the (aliphatic)hydrocarbon radical and 6 to 18 carbon atoms in the alkyl moiety of thealkylphenols.

Further suitable nonionic tensides are the watersoluble polyethyleneoxide adducts, which contain 20 to 250 ethylene glycol ether groups and10 to 100 propylene glycol ether groups, with polypropylene glycol,ethylenediaminopolypropylene glycol and alkylpolypropylene glycol having1 to 10 carbon atoms in the alkyl chain. The compounds mentioned usuallycontain 1 to 5 ethylene glycol units per propylene glycol unit. Examplesof nonionic tensides which may be mentioned are:nonylphenolpolyethoxyethanols, castor oil polyglycol ethers,polypropylene/polyethyleneoxy adducts, tributylphenoxypolyethoxyethanol,polyethylene glycol and octylphenoxypolyethoxyethanol. Suitable also arefatty acid esters of polyoxyethylenesorbitan, such aspolyoxyethylenesorbitan-trioleate.

In the case of the cationic tensides, they are in particular quaternaryammonium salts which contain as N-substituents at least one alkyl grouphaving 8 to 22 carbon atoms and, as further substituents, lower,optionally halogenated alkyl, benzyl or lower hydroxyalkyl groups. Thesalts are preferably in the form of halides, methyl sulfates or ethylsulfates, for example stearyltrimethylammonium chloride orbenzyldi(2-chloroethyl)ethylammonium bromide. In the field coveringstored provisions, the additives which are preferred are those that aresafe for human and animal foodstuffs.

The tensides customarily used in formulation practice are described,inter alia, in the following publications:

"Mc Cutcheon's Detergents and Emulsifiers Annual" MC Publishing Corp.,Ridgewood, N.J., 1981; and

Dr. Helmut Stache "Tensid-Taschenbuch" (Tenside Handbook) Carl HanserVerlag, Munic/Vienna, 1981.

The agrochemical preparations contain as a rule 0.1 to 99%, particularly0.1 to 95%, of active ingredient of the formula II, 99.9 to 1%,especially 99.8 to 5%, of a solid or liquid additive, and 0 to 25%, inparticular 0.1 to 25%, of a tenside.

Whereas commercial products are preferably in the form of concentratedcompositions, the preparations employed by the end-user are as a rulediluted.

The compositions can contain further additives, such as stabilisers,antifoaming agents, viscosity regulators, binders and adhesives, as wellas fertilisers or other active ingredients for obtaining specialeffects.

Agrochemical compositions of the types described herein likewise formpart of the present invention.

The following examples serve to further illustrate the invention withoutlimiting the scope thereof.

PRODUCTION OF THE FINAL PRODUCTS Example F1 Production of ##STR19##4-(2,3-Dichlorophenyl)-3-cyanopyrrole

4.0 g of 3-trifluoromethyl-4-(2,3-dichlorophenyl)-pyrrole, 21 ml of 25%aqueous ammonia and 40 ml of dioxane are stirred for 26 hours at 180° C.in an autoclave. After cooling to room temperature, the reaction mixtureis filtered, and the clear filtrate is concentrated by evaporation. Theresidue is taken up in ethyl acetate, washed with water and subsequentlywith diluted sodium chloride solution, dried over magnesium sulfate,filtered, and concentrated by evaporation. The residue is caused tocrystallise by the addition of hexane; it is then filtered off and driedto thus obtain 3.4 g (100% of theory) of4-(2,3-dichlorophenyl)-3-cyanopyrrole having a melting point of 150° C.

Example F2 Production of ##STR20## 4-(2,3-Dichlorophenyl)-3-cyanopyrrole

6.4 g of N-acetyl-4-(2,3-dichlorophenyl)-3-trifluoromethylpyrrole, 15 mlof 25% aqueous ammonia solution and 60 ml of dioxane are stirred for 18hours at 160° C. in an autoclave. The reaction mixture is cooled to roomtemperature and filtered, and the clear filtrate is concentrated byevaporation. The viscous residue is dissolved in ethyl acetate; thesolution is washed firstly with water and then with a diluted sodiumchloride solution; it is subsequently dried over sodium sulfate,filtered, and concentrated by evaporation. To the residue is addedn-hexane, and the crystals which precipitate are filtered off and dried.The yield is 5.3 g of 4-(2,3-dichlorophenyl)-3-cyanopyrrole, m.p.149°-150° C.

By procedures analogous to those described are also obtained thefollowing compounds of the formula I:

    ______________________________________                                         ##STR21##                     (I)                                            Comp. No.       R.sub.n m.p °C.                                        ______________________________________                                        1               2,3-Cl.sub.2                                                                          149-150                                               2               2-Br    135-138                                               3               2,5-Cl.sub.2                                                                          137-142                                               4               2-Cl    136-138                                               5               3-CF.sub.3                                                                            87-89                                                 6               3-Br    132-134                                               7               3-F     138-139                                               8               3-CH.sub.3                                                                            109-111                                               9               4-F     137-139                                               10              4-Cl    153-155                                               11              2,4-Cl.sub.2                                                                          150-152                                               12              3-Cl    138-140                                               13              H       120-123                                               ______________________________________                                    

FORMULATION EXAMPLES FOR LIQUID ACTIVE INGREDIENTS OF THE FORMULA II(%=PERCENT BY WEIGHT)

    ______________________________________                                        F1. Emulsion concentrates                                                                         (a)      (b)    (c)                                       ______________________________________                                        active ingredient from the Tables                                                                 25%      40%    50%                                       calcium dodecylbenzenesulfonate                                                                    5%       8%     6%                                       castor oil-polyethylene glycol                                                                     5%      --     --                                        ether (36 mols of ethylene oxide)                                             tributylphenol-polyethylene glycol                                                                --       12%     4%                                       ether (30 mols of ethylene oxide)                                             cyclohexanone       --       15%    20%                                       xylene mixture      65%      25%    20%                                       ______________________________________                                    

Emulsions of any required concentration can be produced fromconcentrates of this type by dilution with water.

    ______________________________________                                        F2. Solutions       (a)    (b)    (c)   (d)                                   ______________________________________                                        active ingredient from the Tables                                                                 80%    10%     5%   95%                                   ethylene glycol-monomethyl ether                                                                  20%    --     --    --                                    polyethylene glycol (M.W. 400)                                                                    --     70%    --    --                                    N--methyl-2-pyrrolidone                                                                           --     20%    --    --                                    epoxidised coconut oil                                                                            --     --      1%    5%                                   ligroin (boiling limits 160-190° C.)                                                       --     --     94%   --                                    (M.W. = molecular weight)                                                     ______________________________________                                    

The solutions are suitable for application in the form of very finedrops.

    ______________________________________                                        F3. Granulates         (a)    (b)                                             ______________________________________                                        active ingredient from the Tables                                                                     5%    10%                                             kaolin                 94%    --                                              highly dispersed silicic acid                                                                         1%    --                                              attapulgite            --     90%                                             ______________________________________                                    

The active ingredient is dissolved in methylene chloride, the solutionis sprayed onto the carrier, and the solvent is subsequently evaporatedoff in vacuo.

    ______________________________________                                        F4. Dusts              (a)    (b)                                             ______________________________________                                        active ingredient from the Tables                                                                     2%     5%                                             highly dispersed silicic acid                                                                         1%     5%                                             talcum                 97%    --                                              kaolin                 --     90%                                             ______________________________________                                    

Ready-for-use dusts are obtained by the intimate mixing together of thecarriers with the active ingredient.

FORMULATION EXAMPLES FOR SOLID ACTIVE INGREDIENTS OF THE FORMULA II(%=PERCENT BY WEIGHT)

    ______________________________________                                        F5. Wettable powders  (a)     (b)    (c)                                      ______________________________________                                        active ingredient from the Tables                                                                   25%     50%    75%                                      sodium lignin sulfonate                                                                              5%      5%    --                                       sodium lauryl sulfate  3%     --      5%                                      sodium diisobutylnaphthalene sulfonate                                                              --       6%    10%                                      octylphenolpolyethylene glycol ether                                                                --       2%    --                                       (7-8 mols of ethylene oxide)                                                  highly dispersed silicic acid                                                                        5%     10%    10%                                      kaolin                62%     27%    --                                       ______________________________________                                    

The active ingredient is well mixed with the additives, and the mixtureis thoroughly ground in a suitable mill. Wettable powders which can bediluted with water to give suspensions of the required concentration areobtained.

    ______________________________________                                        F6. Emulsion concentrate                                                      ______________________________________                                        active ingredient from the Tables                                                                    10%                                                    octylphenol polyethylene glycol ether                                                                 3%                                                    (4-5 mols of ethylene oxide)                                                  calcium dodecylbenzenesulfonate                                                                       3%                                                    castor oil polyglycol ether                                                                           4%                                                    (35 mols of ethylene oxide)                                                   cyclohexanone          30%                                                    xylene mixture         50%                                                    ______________________________________                                    

Emulsions of the required concentration can be obtained from thisconcentrate by dilution with water.

    ______________________________________                                        F7. Dusts              (a)    (b)                                             ______________________________________                                        active ingredient from the Tables                                                                     5%     8%                                             talcum                 95%    --                                              kaolin                 --     92%                                             ______________________________________                                    

Dusts ready for use are obtained by mixing the active ingredient withthe carriers and grinding the mixture in a suitable mill.

    ______________________________________                                        F8. Extruder granulate                                                        ______________________________________                                        active ingredient from the Tables                                                                   10%                                                     sodium lignin sulfonate                                                                              2%                                                     carboxymethylcellulose                                                                               1%                                                     kaolin                87%                                                     ______________________________________                                    

The active ingredient is mixed and ground with the additives, and themixture is moistened with water. This mixture is extruded andsubsequently dried in a stream of air.

    ______________________________________                                        F9. Coated granulate                                                          ______________________________________                                        active ingredient from the Tables                                                                    3%                                                     polyethylene glycol (M.W. 200)                                                                       3%                                                     kaolin                94%                                                     (M. W. = molecular weight)                                                    ______________________________________                                    

The finely ground active ingredient is evenly applied in a mixer to thekaolin moistened with polyethylene glycol. Dustfree coated granules areobtained in this manner.

    ______________________________________                                        F.10. Suspension concentrate                                                  ______________________________________                                        active ingredient from the Tables                                                                    40%                                                    ethylene glycol        10%                                                    nonylphenolpolyethylene glycol ether                                                                  6%                                                    (15 mols of ethylene oxide)                                                   sodium lignin sulfonate                                                                              10%                                                    carboxymethylcellulose  1%                                                    37% aqueous formaldehyde solution                                                                    0.2%                                                   silicone oil in the form of a                                                                        0.8%                                                   75% aqueous emulsion                                                          water                  32%                                                    ______________________________________                                    

The finely ground active ingredient is intimately mixed with theadditives. There is thus obtained s suspension concentrate from whichcan be produced, by dilution with water, suspensions of theconcentration required.

BIOLOGICAL EXAMPLES Example B1 Action against Botrytis cinerea on beans

Residual-protective action

Bean plants about 10 cm in height are sprayed with a spray liquorprepared from wettable powder of the active ingredient (0.02% of activeingredient). The plants are infested after 48 hours with a conidiosporesuspension of the fungus. The extent of fungus infection is assessedafter incubation of the infested plants for 3 days at 21° C. with95-100% relative humidity.

The compounds from the Tables greatly reduce fungus infection not onlyin the above model test but also in the field test. At a concentrationof 0.02%, compounds which prove fully effective (infection 0 to 5%) arefor example compounds Nos. 2.1, 2.4, 2.14, 2.17 and 2.37. Infection onuntreated but infested bean plants is 100%.

Example B2 Action against Botrytis cinerea on apples

Artificially damaged apples are treated by applying drops of sprayliquor, prepared from wettable powder of the the active substance, tothe damaged areas on the apples. The treated fruit is then inoculatedwith a spore suspension of Botrytis cinerea, and is incubated for oneweek at about 20° C. with high relative humidity.

For an assessment of the results, the decayed areas of damage arecounted, and from the number is deduced the fungicidal action of thetest substance. Amongst other effective compounds tested, the compoundsNos. 2.1, 2.4, 2.14, 2.17 and 2.37 completely prevent fungus infection,whereas the level of infection on untreated control fruit is 100%.

What is claimed is:
 1. The compound of the formula ##STR22## wherein Ris halogen, C₁ -C₆ -alkyl or C₁ -C₆ -haloalkyl,n is 0, 1 or 2, and R₁ ishydrogen or the group C(O)R₂, in which R₂ is C₁ -C₆ -alkyl, C₁ -C₆-haloalkyl, phenyl or C₁ -C₆ -alkoxy.
 2. A compound of claim 1, whereinR is chlorine, n is 1 or 2, and R₁ has the meanings defined in claim 1.3. A fungicidal composition comprising an effective amount of a compoundof claim 1, together with customary carriers and additives.
 4. A processfor controlling fungi which damage plants, which process comprisesapplying to the plants or to the locus thereof a fungicidally effectiveamount of a compound of claim 1.